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I am currently designing an interocitor, which emits dark light by inducing a current of anti-plasmons through some bendy plastic straws and a chronosynclastic infindibulator. Science!

Not everyone is paying attention to reality. While it offers some comic relief for those who are, perhaps in parallel it loops into the fold those who were previously oblivious, intentionally or otherwise. It’s an overly optimistic and hopeful stretch, I know, but maybe a few people will watch and be like, “hmm… hadn’t really thought of it that way before, but this is sort of what’s been happening all around me IRL.” In the end, it’s just a movie, a dark comedy. It’s a way to pass 2 hours and take your mind off your troubles for a little bit.

I watched this over the weekend. Overall I thought it was a humorous, provocative, and scarily accurate depiction of what happens when human beings are confronted with a dire threat (in this case an extinction level event arising from a direct hit by a 5-10 km wide comet). Meryl Streep's character, President Orlean, was very well written. She's basically the female Trump, governing an administration infested with nepotism, corruption, and private donors. Interestingly this film was panned by critics - perhaps because it's message about the superficiality of the media hit a little too close to home. Synopsis from IMDB: "Kate Dibiasky (Jennifer Lawrence), an astronomy grad student, and her professor Dr. Randall Mindy (Leonardo DiCaprio) make an astounding discovery of a comet orbiting within the solar system. The problem - it's on a direct collision course with Earth. The other problem? No one really seems to care. Turns out warning mankind about a planet-killer the size of Mount Everest is an inconvenient fact to navigate. With the help of Dr. Oglethorpe (Rob Morgan), Kate and Randall embark on a media tour that takes them from the office of an indifferent President Orlean (Meryl Streep) and her sycophantic son and Chief of Staff, Jason (Jonah Hill), to the airwaves of The Daily Rip, an upbeat morning show hosted by Brie (Cate Blanchett) and Jack (Tyler Perry). With only six months until the comet makes impact, managing the 24-hour news cycle and gaining the attention of the social media obsessed public before it's too late proves shockingly comical - what will it take to get the world to just look up?" https://www.imdb.com/title/tt11286314/

https://www.nasa.gov/feature/the-universe-s-first-type-of-molecule-is-found-at-last The first type of molecule that ever formed in the universe has been detected in space for the first time, after decades of searching. Scientists discovered its signature in our own galaxy using the world’s largest airborne observatory, NASA’s Stratospheric Observatory for Infrared Astronomy, or SOFIA, as the aircraft flew high above the Earth’s surface and pointed its sensitive instruments out into the cosmos. When the universe was still very young, only a few kinds of atoms existed. Scientists believe that around 100,000 years after the big bang, helium and hydrogen combined to make a molecule called helium hydride for the first time. Helium hydride should be present in some parts of the modern universe, but it has never been detected in space — until now. SOFIA found modern helium hydride in a planetary nebula, a remnant of what was once a Sun-like star. Located 3,000 light-years away near the constellation Cygnus, this planetary nebula, called NGC 7027, has conditions that allow this mystery molecule to form. The discovery serves as proof that helium hydride can, in fact, exist in space. This confirms a key part of our basic understanding of the chemistry of the early universe and how it evolved over billions of years into the complex chemistry of today. The results are published in this week’s issue of Nature. more at link................. the paper: https://arxiv.org/ftp/arxiv/papers/1904/1904.09581.pdf First astrophysical detection of the helium hydride ion (HeH+ ) During the dawn of chemistry1,2 when the temperature of the young Universe had fallen below ~4000 K, the ions of the light elements produced in Big Bang nucleosynthesis recombined in reverse order of their ionization potential. With its higher ionization potentials, He++ (54.5 eV) and He+ (24.6 eV) combined first with free electrons to form the first neutral atom, prior to the recombination of hydrogen (13.6 eV). At that time, in this metal-free and low-density environment, neutral helium atoms formed the Universe’s first molecular bond in the helium hydride ion HeH+ , by radiative association with protons (He + H+ → HeH+ + hν). As recombination progressed, the destruction of HeH+ (HeH+ + H → He + H2 + ) created a first path to the formation of molecular hydrogen, marking the beginning of the Molecular Age. Despite its unquestioned importance for the evolution of the early Universe, the HeH+ molecule has so far escaped unequivocal detection in interstellar space. In the laboratory the ion was discovered as long ago as 19253 , but only in the late seventies was the possibility that HeH+ might exist in local astrophysical plasmas discussed4,5,6,7. In particular, the conditions in planetary nebulae were shown to be suitable for the production of potentially detectable HeH+ column densities: the hard radiation field from the central hot white dwarf creates overlapping Strömgren spheres, where HeH+ is predicted to form, primarily by radiative association of He+ and H. With the GREAT spectrometer8.9 on board SOFIA10 the HeH+ rotational ground-state transition at λ149.1 µm is now accessible. We report here its detection towards the planetary nebula NGC7027. The mere fact of its proven existence in nearby interstellar space constrains our understanding of the chemical networks controlling the formation of this very special molecular ion.

I'm not so sure. This is an ion, HeH⁺, that is isoelectronic with H₂, i.e. with 2 electrons in a σ-bond formed by overlap of the 2 1s atomic orbitals. Though it will be strongly polar, due to the higher charge on the He nucleus (i.e. the 1s on He will be pulled in and won't overlap so well). I'm sure it is highly reactive: as a cation it will tend to pull electrons off whatever it comes into contact with, and it can easily form He by donating the proton to something. What strikes me about it is that as, unlike H₂ it is polar, it will have a vibrational and rotational spectrum, so presumably can be detected in the IR and microwave regions of the spectrum. P.S. I see there is a Wiki article on it: https://en.wikipedia.org/wiki/Helium_hydride_ion#cite_note-Epa-23 according to which the bond strength is 178kJ/mol, about 40% that of H₂ so quite respectable. Also I notice they think it was a constituent of the primordial plasma, 280,000 yrs before the universe became transparent. So presumably it is not expected to fall apart thermally so easily.

Here it is: Isn’t it conceivable that spacetime is actually flat, but the clocks and rulers with which we measure it, and which we regard as perfect in the sense of Box 11.1, are actually rubbery? Might not even the most perfect of clocks slow down or speed up, and the most perfect of rulers shrink or expand, as we move them from point to point and change their orientations? Wouldn’t such distortions of our clocks and rulers make a truly flat spacetime appear to be curved? Yes. Figure 11.1 gives a concrete example: the measurement of circumferences and radii around a nonspinning black hole. On the left is shown an embedding diagram for the hole’s curved space. The space is curved in this diagram because we have chosen to define distances as though our rulers were not rubbery, as though they always hold their lengths fixed no matter where we place them and how we orient them. The rulers show the hole’s horizon to have a circumference of 100 kilometers A circle of twice this circumference, 200 kilometers, is drawn around the hole, and the radial distance from the horizon to that circle is measured with a perfect ruler; the result is 37 kilometers. If space were flat, that radial distance would have to be the radius of the outside circle, 200/π kilometers, minus the radius of the horizon, 100/π kilometers; that is, it would have to be 200/π – 100/π = 16 kilometers (approximately). To accommodate the radial distance’s far larger, 37-kilometer size, the surface must have the curved, trumpet-horn shape shown in the diagram. If space is actually flat around the black hole, but our perfect rulers are rubbery and thereby fool us into thinking space is curved, then the true geometry of space must be as shown on the right in Figure 11.1, and the true distance between the horizon and the circle must be 16 kilometers, as demanded by the flat-geometry laws of Euclid. However, general relativity insists that our perfect rulers not measure this true distance. Take a ruler and lay it down circumferentially around the hole just outside the horizon (curved thick black strip with ruler markings in right part of Figure 11.1). When oriented circumferentially like this, it does measure correctly the true distance. Cut the ruler off at 37 kilometers length, as shown. It now encompasses 37 percent of the distance around the hole. Then turn the ruler so it is oriented radially (straight thick black strip with ruler markings in Figure 11.1). As it is turned, general relativity requires that it shrink. When pointed radially, its true length must have shrunk to 16 kilometers, so it will reach precisely from the horizon to the outer circle. However, the scale on its shrunken surface must claim that its length is still 37 kilometers, and therefore that the distance between horizon and circle is 37 kilometers. People like Einstein who are unaware of the ruler’s rubbery nature, and thus believe its inaccurate measurement, conclude that space is curved. However, people like you and me, who understand the rubberiness, know that the ruler has shrunk and that space is really flat. What could possibly make the ruler shrink, when its orientation changes? Gravity, of course. In the flat space of the right half of Figure 11.1 there resides a gravitational field that controls the sizes of fundamental particles, atomic nuclei, atoms, molecules, everything, and forces them all to shrink when laid out radially. The amount of shrinkage is great near a black hole, and smaller farther away, because the shrinkage-controlling gravitational field is generated by the hole, and its influence declines with distance. The shrinkage-controlling gravitational field has other effects. When a photon or any other particle flies past the hole, this field pulls on it and deflects its trajectory. The trajectory is bent around the hole; it is curved, as measured in the hole’s true, flat spacetime geometry. However, people like Einstein, who take seriously the measurements of their rubbery rulers and clocks, regard the photon as moving along a straight line through curved spacetime. What is the real, genuine truth? Is spacetime really flat, as the above paragraphs suggest, or is it really curved? To a physicist like me this is an uninteresting question because it has no physical consequences. Both viewpoints, curved spacetime and flat, give precisely the same predictions for any measurements performed with perfect rulers and clocks, and also (it turns out) the same predictions for any measurements performed with any kind of physical apparatus whatsoever. For example, both viewpoints agree that the radial distance between the horizon and the circle in Figure 11.1, as measured by a perfect ruler, is 37 kilometers. They disagree as to whether that measured distance is the “real” distance, but such a disagreement is a matter of philosophy, not physics. Since the two viewpoints agree on the results of all experiments, they are physically equivalent. Which viewpoint tells the “real truth” is irrelevant for experiments; it is a matter for philosophers to debate, not physicists. Moreover, physicists can and do use the two viewpoints interchangeably when trying to deduce the predictions of general relativity. Thorne, Kip. Black Holes & Time Warps: Einstein's Outrageous Legacy (pp. 400-401).

Let me try to explain this a bit more. In a local gauge symmetry, you apply a smooth and continuous transformation to your fields at every point in spacetime, and the parameters of the transformation can vary from point to point (in global gauge symmetries, the parameters are taken to be the same everywhere). You do this by replacing the ordinary derivatives in your Lagrangian by appropriately defined gauge-covariant derivatives. For example, in QED the gauge group is U(1), so the transformation is essentially a rotation by some angle, and the corresponding gauge-covariant derivative introduces a new rank-1 object in the Lagrangian - which is just the electromagnetic vector potential, and thus the photon field. So what does this mean? Local gauge symmetry means that fields have redundant degrees of freedom that allow a very specific type of change to happen in the field configuration at each point. Since the symmetries are continuous, by Noether’s theorem this corresponds to the existence of a conserved quantity (a charge of some kind). Consistent changes in field configuration plus conserved current equals an interaction between fields. So this is the central idea - redundant degrees of freedom (local gauge symmetries), consistently defined across all fields at each point on spacetime, allows for interactions between fields, and the interaction mechanism is itself a new field, as is apparent by the formalism of gauge-covariant derivatives. Without gauge symmetry, fields wouldn’t have any way to interact in this self-consistent manner. Note that in a global sense (accounting for all fields at all points in spacetime) nothing really changes at all, because all interaction currents are made up of conserved quantities - you still have the same Lagrangian after an interaction happens. All you do is ‘shift things around’, so to speak. This is the great beauty of it. This can be very elegantly described as connection forms (called gauge potential) on fiber bundles, so a knowledgable of differential geometry is very helpful here.

My sarcasmometer is going through the roof!

Yes, this is certainly so in the classical EM. However in QED these EM gauge transformations are coupled with local phase transformations of charged particles and this creates the mechanism of their interactions. This gauge symmetry I am asking about.

It essentially just means that our description of the physics in question is over-determined, ie that there are superfluous degrees of freedom in the chosen mathematical formalism. These can be either local or global. This is why you can make specific changes to the fields without affecting the physics.

I think you are focussing far too much on a single phenomenon, whereas metric expansion actually serves as a coherent model for a whole host of different observational data points. It isn’t only about redshift by any means. Note that we are talking cosmological redshift here, and not the Doppler effect or any other frequency shifting - my impression is that you haven’t understood the difference. The other thing is that metric expansion is an unavoidable consequence of the laws of gravity - if you feed basic cosmological assumptions into the field equations, then any solution you get out will have an intrinsic tendency to metrically expand (ie some of the metric coefficients will necessarily be time-dependent). This is mathematical fact. So, if you postulate a static universe of any kind, you’ll need to explain how metric expansion does not happen, in addition to those observations that are difficult to explain without expansion. The only way to really do that is to postulate amendments to the laws of gravity, which takes you down into a really, really deep rabbit hole. So, based on current knowledge and data, metric expansion is simply the most coherent explanation that covers the widest range of observations without having to postulate any new physics.

The usual answer for these type of questions is " it depends" . If you just freeze at one point, the ice will just slide along the pipe, when the pressure builds up. Ideally, to split the pipe, you need a substantial length to freeze, with the ends freezing before the centre, to contain the pressure.

I saw the movie and enjoyed it. Personally, I think real politicians would have fared worse in a similar crisis. Humanity is facing a climate change crisis. All the politicians have done is raise taxes on CO2 emissions, which has only hit ordinary people in the pockets.. Any reason to raise taxes is good for politicians, all kinds of politicians.. People who have less money in their pockets are less likely to buy expensive electric cars, install renewable power generators, upgrade their homes to zero emission, etc. etc. Which causes people to turn away, to become discouraged, to start fighting change because it affects them personally.. If a crisis similar to the one depicted in the movie were to happen for real, we can expect to see taxes raised..

"Are Vegan's, a help or a hindrance to, our future?" Vegans may well be less of a problem than people who misuse apostrophes.

Anonymization of exams is a good idea. A person should be judged by knowledge, not by the surname or the depth of the pockets of the parents.

In the absence of a self-consistent model of quantum gravity, we do not yet know the underlying mechanism that makes gravity work the way it does. General Relativity is an effective description of the large-scale dynamics of gravity, and as such it is very successful; but it has nothing to say about the underlying nature of spacetime. That is outside its domain. For the same reason we also don’t know yet what exactly went on prior to about 10^-35s after the BB. This, however, does not cast doubt on the fact that the BB happened, because this is an inference based on extrapolation from current observational data.

He has already had that explained to him by a couple of others Marcus. 🙄 No, sorry, again wrong. DE is the entitiy/unknown reason to explain the acceleration in the expansion rate.

It has already been explained to you that other aspects of cosmology like universal expansion over large scales, gravity, etc are all overwhelmingly supported scientific theories. Yet we do not understand the mechanism that drives them. Are you denying gravity exists because we are unable to ascribe a mechanism? Or are you ladened down with so much baggage and agenda, that you are sticking your fingers in your ears. That's what some call trolling. Evidence for the BB: (1)The observed expansion. (2) The relic left over heat known as the CMBR (3) The abundence of the lighter elements (4) Galactic distribution.

A mechanism can only be proposed once you have a theory. At least in physics and chemistry. I've told you in another thread, but you didn't answer. Newton's laws of motion don't come from a mechanism Maxwell's equations of electromagnetism don't come from a mechanism Einstein's equations of gravity don't come from a mechanism And so on. In the case of cosmology, the big bang is an inevitable consequence of Einstein's equations plus reasonable --and observationally sound-- cosmological hypotheses (cosmological principle, Hubble's law...). When extrapolated backwards in time, an expanding universe leads to a time in the remote past when everything was much, much closer together. There's your bang. Seems to make sense, doesn't it?

Its not, they are actually observed to be in the same plane. This contradicts the aberration that gravity is caused by a curvature of space-time and planets orbit on the curved space. As does the flat geometry of the universe in general. There is nothing curved or bent. You are not getting the point, Einstein. This is exactly where Einsteins theory is applicable in our solar system, and it is exactly where it fails to explain the orbits off all the planets, which are all in the same flat plane- which makes no sense if SPACE IS CURVED. So now you explain Einstein's gravity with Newton's law, are you fucking joking ? Einstein contradicts Newton, he says gravity is not a force but a curvature of space-time, while Newton says gravity is a force in a flat space ! There is no problem between Newtons theory and the planets orbiting in a flat plane, like you mention it is perfectly explainable using Newton's law, but there is a huge problem in the case of Einsteins theory, which cannot explain why the planets orbit in the same flat plane if the space in which they orbit is curved. If its not an actual bending of anything then why do mainstream scientists keep pretending that it is ('matter tells space how to curve, and space tells matter how to move'), and keep giving the same fabric sheet example over and over ? And how is the aberration in the video an accurate description of reality ? Do you seriously think that it has anything to do with reality ? Where do you think you are, the Matrix ?

Supported by what ?! By mere assumptions such as redshift is caused by space expansion, and by self-contradicting theories which predict contracting, then static, then expanding universes as time goes by ? I dont understand the mechanism that drives tired light either. But I have to explain in front of you, while you dont have to explain anything. No, Einstein ! I am simply asking you to respect your own standards which you impose to others. You asked me to give a mechanism for the tired light (or energy loss of light over vast distance) and closed the thread because I couldn't ! Now I ask you to give a mechanism for space expansion/big bang ! What is it so hard to understand ?? You really get it do you ?

Since I understand that there is a very high standard on this forum which requires a mechanism for every theory, and not just an ideea, then I think you too are required to respect your own standards and give a mechanism for the theories that you support. So what is the mechanism that you propose for the Big-Bang ?

History Einstein included the cosmological constant as a term in his field equations for general relativity because he was dissatisfied that otherwise his equations did not allow, apparently, for a static universe: gravity would cause a universe that was initially at dynamic equilibrium to contract. To counteract this possibility, Einstein added the cosmological constant.[3] However, soon after Einstein developed his static theory, observations by Edwin Hubble indicated that the universe appears to be expanding; this was consistent with a cosmological solution to the original general relativity equations that had been found by the mathematician Friedmann, working on the Einstein equations of general relativity. Einstein reportedly referred to his failure to accept the validation of his equations—when they had predicted the expansion of the universe in theory, before it was demonstrated in observation of the cosmological redshift—as his "biggest blunder". [WIKIPEDIA] @beecee But you see, Einstein never predicted the expansion with his theory. He predicted the exact opposite, a CONTRACTION, and initially rejected an expansion (proposed by Friddman ), because he was too occupied to doctor his theory in order to comply with a static universe, -which was the belief of the time. That is not a scientific aproach, it is a totally pseudo-scientific aproach. And that is not a scientific theory, because it obviously contradicts itself. As, depending on the man who is solving the equations, it gives opposite results ! And btw, makes Einstein look a bit silly not being able so solve his own equations ! This is not the genius that I had in mind. It is important to note that someone else predicted an expansion based on his theory, expansion which he rejected, and only after Hubble saw the redlight accepted. But this was his THIRD TRY. I wonder how many scientists are given so many shots to 'prove' their theories. In the end Einsteins GR 'predicted' all possible states of the universe: contracting, static, and expanding ! So whatever state the universe was in, his theory could not be wrong ! Because Einstein simply changed the theory's outcome according to 'the beliefs of the time'.

Its called Dark Light. Dark Light in a mysterious light which chases bright light until it tires and looses energy, causing it to drop it's cadence (or frequency) and shift to red. This is sooo going Mainstream. No, it's not a joke. It's SCIENCE.